Been done a couple of times and always had my money refunded and through a very simple process. On one occasion it was only for a small amount, which would have gone unnoticed except I quieried my statement with the bank. First time the bank spotted it before I found out. My worst case scenarios are when I am doing a lot of spending away from home or I buy something expensive abroad, and suddenly find my card has been blocked by my bank as they suspect fraud.
Last time it happened a couple of years ago I was in a restaurant and tried to pay by card to find it had been blocked which was embarrasing, fortunatley I was well known in the restaurant but it took 15 minutes over the phone, late at night, being questioned by some foreigner abroad, probably India, who could hardly speak the Queens English questioning me over my spending habits. It boiled down to the fact that I had bought my son an expensive guitar in Germany online and my card was blocked. Now I have two cards which I take with me if I travel afar so I always have a backup account. Afar can be quite close too, spent a fortune in Newcastle one day and found my card blocked the next day. Being a creature of habit, I rarely go away so any excessive spending suddenly somewhere from my local vicinity sets the bells ringing in the bank to suspect foul play.